World War II is getting updated with a new dev diary, the final one before a break that will last until August. Any news of World War II being relevant today are bad news, but not so when HOI 4 is in question.
As part of the newest Barbarossa expansion, the developers have noticed that micromanaging supply routes is becoming far too time-consuming, and frankly, irritatingly inefficient, and so are looking to fix these issues.
Supply flows are now better represented on maps, and easier to control. It's now possible for divisions to supply from multiple hubs. Trucks are now less of a strict necessity, but rather something you can assign to hubs to make sure they can project supplies further away.
Converting railways, hub maximum capacity, and other important information is now fully available at the drop of a hat and will give players an easier time when calculating how many munitions they can transport, or how many mouths their country is capable of feeding.
Motorization will play a big role in the future as well. It is now possible to toggle the motorization level of supply hubs, as well as armies. However, as with anything in Paradox games, there is a price to upgrading these hubs. Motor vehicles have to come from somewhere, and the truck supply will suffer due to these upgrades, though the range will increase.
The Mulberry Harbors, on the other hand, interfere with warfare directly. No longer are naval invasions an "all or nothing" gambit. These Harbors are only available if researched to a sufficient level, and are artificial harbors placed near the landing zones of an invasion. They supply your troops with all kinds of supplies and make it less of a priority to take an enemy harbor in the first attack.
Though enemy harbors are still a priority, however, as these Harbors are not meant to last forever, but are temporary, and so are their supplies. Factors such as the quality of Enemy Air Superiority are in play when calculating how long a Mulberry Harbor will last.